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Velocity-resolved [O I] 63 µm Emission in the HD 50138 Circumstellar Disk
de Wit, W. -J.; Güsten, R.; Wiesemeyer, H. +5 more
HD 50138 is one of the brightest B[e] stars and is located at a distance of ∼380 pc with strong infrared excess. The star was observed in [O I] 63 µm and [C II] 158 µm with high velocity resolution with upGREAT on SOFIA. The velocity-resolved [O I] emission provides evidence for a large gas disk, ∼760 au in size, around HD 50138. Where…
High-resolution Observations of Cen A: Yellow and Red Supergiants in a Region of Jet-induced Star Formation?
Nishiyama, S.; Labadie, L.; Britzen, S. +5 more
We present the analysis of near-infrared (NIR), adaptive optics Subaru and archived HST imaging data of a region near the northern middle lobe of the Centaurus A (Cen A) jet, at a distance of ∼15 kpc northeast from the center of NGC5128. Low-pass filtering of the NIR images reveals a strong—> 3σ above the background mean—signal at the expected …
SOFIA/FORCAST Observations of the Luminous Blue Variable Candidates MN 90 and HD 168625
Smith, Nathan; Gehrz, Robert D.; Shenoy, Dinesh +1 more
We present Stratospheric Observatory for Infrared Astronomy (SOFIA)/Faint Object infraRed CAmera for the SOFIA Telescope (FORCAST) imaging of the circumstellar dust shells surrounding the luminous blue variable candidates MN 90 and HD 168625 to quantify the mineral abundances of the dust and to constrain the evolutionary state of these objects. Ou…
Limits on the Contribution of Endogenic Radiolysis to the Presence of Molecular Oxygen in Comet 67P/Churyumov-Gerasimenko
Mousis, Olivier; Bouquet, Alexis; Nicolaou, Georgios +6 more
Radiolytic production has been proposed as a potential source for the molecular oxygen observed in comet 67P/Churyumov-Gerasimenko. Radiolysis can be exogenic or endogenic, the latter due to radionuclides present in the dust constitutive of the comet nucleus. We investigated the possibility of forming a significant amount of molecular oxygen throu…
KIC 2568888: To Be or Not to Be a Binary
García, R. A.; De Ridder, J.; Mints, A. +4 more
In cases where both components of a binary system show oscillations, asteroseismology has been proposed as a method to identify the system. For KIC 2568888, observed with Kepler, we detect oscillation modes for two red giants in a single power-density spectrum. Through an asteroseismic study we investigate if the stars have similar properties, whi…
The Dust-selected Molecular Clouds in the Northeast Region of the Small Magellanic Cloud
Kohno, Kotaro; Bot, Caroline; Yun, Min S. +19 more
We present a high-sensitivity (1σ < 1.6 mJy beam-1) continuum observation in a 343 arcmin2 area of the northeast region of the Small Magellanic Cloud at a wavelength of 1.1 mm, conducted using the AzTEC instrument on the ASTE telescope. In the observed region, we identified 20 objects by contouring 10σ emission. Through sp…
Recurrent Outbursts Revealed in 3XMM J031820.8-663034
Weng, Shan-Shan; Zhao, Hai-Hui; Wang, Jun-Xian
3XMM J031820.8-663034, first detected by ROSAT in NGC 1313, is one of a few known transient ultraluminous X-ray sources (ULXs). In this paper, we present decades of X-ray data of this source from ROSAT, XMM-Newton, Chandra, and the Neil Gehrels Swift Observatory. We find that its X-ray emission experienced four outbursts since 1992, with a typical…
A-type Stellar Abundances: A Corollary to Herschel Observations of Debris Disks
Matthews, Brenda; Draper, Zachary H.; Kennedy, Grant +3 more
In order to assess the relationship between metallicity and exoplanetary systems, we compare the abundances of AF-type main-sequence stars with debris disk properties assessed using Herschel observations of an unbiased survey of nearby stars. Hot stars are not as commonly observed, given their unique constraints in data reduction, lack of metal li…
Calvera: A Low-mass Strangeon Star Torqued by Debris Disk?
Ge, Mingyu; Xu, Renxin; Li, Yunyang +3 more
Calvera is a unique 59 {ms} isolated pulsar, because it cannot be detected by radio, optical, and gamma-rays; however, it is detectable through the purely thermal emission in soft X-rays. It is suggested that Calvera could be an ordinary middle-aged pulsar with significant magnetospheric activity at a large distance. Alternatively, it is proposed …
Kinematic Identification of Young Nearby Moving Groups from a Sample of Chromospherically Active Stars in the RAVE Catalog
Suárez, Genaro; Aguilar, Luis; Downes, Juan José +2 more
The purpose of this study is the identification of young (1 < age < 100 Myr), nearby (d ≤ 100 pc) moving groups (YNMGs) through their kinematic signature. YNMGs could be the result of the recent dispersal of young embedded clusters, such that they still represent kinematically cold groups, carrying the residual motion of their parental cloud…